1. Field of the Invention
The present invention relates, in general, to a method for making a fresh, unripened cheese analog by incorporating isolated soy protein. The invention also relates to fresh, unripened cheese analog.
2. Background Information
While the art of cheesemaking has been practiced for centuries, the cheesemaker is always looking for ways to improve the finished cheese yield obtained from the starting quantity of milk. This becomes very important in areas of the world where the milk supply is limited. Attempts have been made over the years to incorporate soy protein as an economic replacement for milk proteins. Problems can be encountered due to differences between milk and soy proteins in molecular and functional properties which can affect the quality of the finished cheese.
Therefore, a method is provided which incorporates isolated soy protein into a coagulated milk matrix.
The invention provides a method for making a fresh, unripened cheese analog comprising, (a) mixing isolated soy protein and milk; (b) coagulating the mixture in (a); (c) cutting the product resulting from (b); (d) agitating the product resulting from (c) for about 40 to about 60 minutes at a temperature selected from the range of about 30xc2x0 C. to about 50xc2x0 C.; (e) separating about 50 to about 80% of whey from product resulting from (d); and (f) placing product resulting from (d) in molds and placing molds at a temperature of at least about 28xc2x0 C. for about 2 to about 8 hours.
The invention provides a method for making a fresh, unripened cheese analog comprising, (a) mixing isolated soy protein and milk; (b) coagulating the mixture in (a); (c) cutting the product resulting from (b); (d) agitating the product resulting from (c) for about 40 to about 60 minutes at a temperature selected from the range of about 30xc2x0 C. to about 50xc2x0 C.; (e) separating about 50 to about 80% of whey from product resulting from (d); and (f) placing product resulting from (d) in molds and placing molds at a temperature of at least about 28xc2x0 C. for about 2 to about 8 hours.
The milk used in the present invention may be present in amounts of from about 95% to about 99%, and preferably from about 98% to about 99%. The milk may comprise of from about 0% to about 10% fat and preferably from about 0.5% to about 5% fat. It may be desirable to use milk with a low fat content and optionally add fat from other sources. As such, the fat contained in the milk may originate from at least one of the compounds of the group comprising milkfat or vegetable oil.
The invention provides the above and below described methods wherein said soy protein is present in amounts of from about 10% to 100% by weight, and preferably from about 15% to about 50%. By xe2x80x9cpercentxe2x80x9d it is meant weight percent based on the calculated amount of casein solids in the milk. The isolated soy protein used in the present invention may be prepared by pH adjusting soy curd prior to spray drying or by blending different isolated soy proteins to obtain the desired pH. The pH of the isolated soy protein(s) may be of from about 3 to about 7, and preferably of from about 4.5 to about 6.0.
In one embodiment, the present invention provides a method of making a cheese analog by adding at least one compound to a mixture of isolated soy protein and milk, wherein said compound is selected from the group comprising transglutaminase, starch, a whitening agent, hydrocolloid gum, calcium chloride, and a coagulating enzyme.
Transglutaminase is an enzyme which crosslinks proteins and which aids in crosslinking the isolated soy protein and milk proteins. The transglutaminase catalyzed crosslinks serve to compatibilize the soy and milk proteins. These crosslinks help in improving the functionality of the different proteins and therefore improving the texture of the finished product. Transglutaminase is preferably present in amounts from about 0% to about 1.0%, and preferably from about 0% to about 0.2%.
As a binder or filler in the cheese, generally any starch which is at least partially soluble in water at the described temperatures can be employed in the cheese analog making method of the present invention. Corn and potato starches are types of binder that may be used. The preferred starch should be pregelatinized by mixing with water and heating to its gelatinization temperature prior to addition to the milk. The gelatinized starch may optionally be added in amounts of from about 0% to about 20%, and preferably from about 0% to about 10%.
Often it is desirable to produce a cheese analog with a white appearance. As such, the present invention provides for the optional addition of a whitening agent in amounts of from about 0% to about 0.5%, preferably from about 0% to about 0.1%. The whitening agent must be chemically inert and harmless to the animal or human who ingests the agent, but, of course also must make the appearance of the cheese white. The invention provides the herein described methods wherein said whitening agent may be selected from the group comprising titanium dioxide, benzoyl peroxide, or green and blue food colorings.
A hydrocolloid gum may be optionally added as a stabilizer to improve the yield of the cheese, and may be added in amounts of from about 0% to about 2%, and preferably from about 0% to about 0.8%. The hydrocolloid gum can be selected from the group comprising carrageenan, carob bean, guar and xanthan.
The invention provides a method for producing a soft, sliceable, unripened cheese-like product. Firming agents may optionally be added to firm the curd. Preferably, calcium chloride is added to produce a firm cheese curd and can be added in amounts of from about 0% to about 0.5%, preferably from about 0% to about 0.2%.
Following step (a), above, a coagulating enzyme may be used to speed the coagulation process, and may be added in catalytic amounts. The coagulating enzyme may be selected from the group comprising rennet and its synthetic equivalents. Preferred rennet preparations can be selected from the group comprising AmericanPure, (SBI-Systems Bio-Industries, calf rennet purified via ion-exchange), Chy-Max (Pfizer, fermentationxe2x80x94using Escherichia coli K-12), Chymogen (Chris Hansen, fermentationxe2x80x94using Aspergillus niger var. awamori), ChymoStar (Rhxc3x4ne-Poulenc, fermentationxe2x80x94using Aspergillus niger var. awamori), Maxiren (Gist-Brocades, Fermentationxe2x80x94using Kluyveromyces marxianus var. lactis), Novoren (Marzyme GM) (Novo Nordisk, Fermentationxe2x80x94using Aspergillus oryzae). Kosikowski, F. V. and Mistry, V. V. (1997), xe2x80x9cCheese and Fermented Milk Foods,xe2x80x9d 3rd edn., F. V. Kosikowski, L. L. C., Westport, Conn., pp. 395 and 698.
A mixture comprising curds and whey results after step (d), above. The whey may be separated from the remainder of the above and below described mixtures by at least one of the methods selected from the group comprising draining, straining and filtering. Preferably, said separating results in elimination of from about 50% to 80% of the whey, and even more preferably, results in elimination of from about 60 to 70% of the whey.
After separating a percentage of the whey from the rest of the above described mixtures, the mixture is salted to improve flavor and texture. The salting agent can be selected from the group comprising sodium chloride. The salted mixture is poured into molds to shape the cheese. The mixture in the molds may also optionally be externally pressed to remove more moisture from the cheese analog. The resulting cheese composition after step (f) comprises from about 2% to about 17% soy isolate.
The present invention is described in further detail in the following non-limiting examples.